For the most effective handling of a herd of cows during the breeding season it is important that cows in estrus be identified promptly and separated from the herd for either natural or artificial insemination, a cow being fertile for only about twelve hours during a twenty-one day period of estrus.
It is well known that cows in a herd when they are in heat will permit another animal to mount them for an appreciable time but other wise will reject the mount immediately. The indentification of cows in heat has been accomplished traditionally by observation, the cows seen to allow mounting by other cows being separated from the herd. This required continuous observation of the herd during the breeding season in order to separate the cows in heat as promptly as possible. The heat detectors as presently employed provide a visible indication such that any cows which have been mounted for a predetermined length of time, say five seconds, can be identified without observation of the act of mounting. Thus detection may be accomplished by periodic inspection of the herd rather than by continuous observation.
Various methods and devices have been employed for the purpose of determining which cows are in heat. An effective estrus detecting device in general use today is that disclosed in U.S. Pat. No. 3,076,431 issued to Wilbur E. Rule and Carl D. Smith on Feb. 5, 1963. This device comprises a small fabric patch which may be cemented to the rump of the cow. The patch contains a small tube containing colored fluid, the fluid of which is released to the patch when the tube is under sufficient pressure for a predetermined time. The cow which has been mounted for a preselected length of time can then be detected by the color appearing on the patch.
Various paint-like substances have also been tried for use in heat detection, these substances being applied to the rump of the cow. The substantial rubbing off or spreading of the paint is then relied on as an indication of mounting.
It is an object of the present invention to provide an improved estrus detecting substance which may be applied to cows in the manner of paint or will be other wise spreadable and will provide a positive and easily observed indication of mounting by another animal.
It is another object of theis invention to provide an improved method and substance for detecting estrus in cows which will provide a readily observed change in color of a patch of the substance resulting from the mounting of a cow on which the substance has been applied.
It is a further object of this invention to provide an easily applied and inexpensive substance which may be employed effectively for the detection of estrus in cows.
Further objects and advantages of this invention will become apparent as the following description proceeds.